Development of Adaptive Sitting Cum Standing Positional Device - User's Centric Approach

Introduction

UNICEF reports in assistive technology for children with disabilities. In 2015, UNICEF estimated the number of children with disabilities under age 18 as 150 million.¹ In India Census 2011, population of the children with disabilities were staged according to age of the children.2 Population of children with disabilities was 1.14% in the age group of 0-4 years, 1.54% in the age group 5-9 years and 1.82% in age group 10-19 years.² Cerebral palsy (CP) affects 3.8% Indians, or roughly 15-20% of physically challenged children. An estimated 3/1000 live births are affected in India.²

The disorders covered by the term CP are very heterogeneous, both in clinical symptoms and in lesions causing these symptoms.³ Many studies reported that severity of impairments is extremely variable. Almost one-third of children with CP are non-ambulant and spend most of their lives in a sitting or lying position.³ Many authors made attempts throughout the years to define CP. Kuban KCK and Alan Leviton reported most recent consensus definition of CP as, "an umbrella term covering a group of non-progressive, but often changing, motor impairment syndromes.⁴

The studies stated that proper positioning including sitting and standing is the base for performance of many skills, especially in children with motor problems. Without proper position, children are less likely to reach their potential for walking, communication, play, selfhelp. Correct positioning reduces the energy the child uses to hold a position and allows children to concentrate on other skills. In poor position, children may be unsure where their bodies are in specific space or feel unsafe in that position. Properly fitted positioning equipment helps children interact with their environment and be more independent in play, learning and self-care.^5,6

The basic positions like sitting and standing are supported using adaptive positioning devices in children with delayed milestones. Research proved that proper positioning using adaptive equipment help children to use more normal postures and in movements to perform skills more easily. Each of these devices is necessary for a child at phases of growth. Positioning requires changes as the children grow, having new medical needs, and/ or with skill development which increases the finical burden in low-income families.^5,6 Despite the widespread clinical use of positional device among children with delayed milestones, little is known about how seating technology affect children with CP at home.⁷ To close this knowledge gap and with feedback from the parents, we were motivated to develop an adjustable, durable, cost effective positional device that can be used for both sitting and standing functions, i.e., for dual purpose.

Materials and Methodology

Product designing

Team approach is very important for the whole team to be involved in creating a piece of adaptive device. Each member of the team has a unique perspective about the child that can help in building most appropriate piece of device with necessary adaptions. The "team" is comprised of the child, family, physician, therapists (physical therapist, occupational therapist, and speech-language pathologist, orthotist, engineer, and designer), medical equipment suppliers and educators or other interventionists.^8-10

For designing this innovative twin device, a team was formed including a Physiotherapist, Orthotist, Assistive technology assistant, a Carpenter at Mobility India, Bengaluru, and a Postgraduate engineering student from IIT-Bombay. The innovators interacted with users, parents, and school teachers of children with delayed milestones to know the status of the currently available seating and standing devices. Parents always had concerns about changing or repurchasing devices as children advance in age. The aim of this study was to build a single product that could be utilised for both sitting and standing functions which can be adjusted as the child grows without comprising the core functionality.

The study hypothesis was that this innovative twin device would have a similar or superior effect on the user's posture, function, and comfort when compared to existing adaptive seating and standing devices (Figure 2). However, results of the interaction and review of literature were coupled and derived to build a simple solution. The data was congregated from the Mobility India Service (MIS) database. The design mapping (Table 1) describes the design and its keys elements.

The unique selling points of the device are stability in siting and standing position, easy manoeuvrability and convenient for storage at home and schools. Adjustability in leg rest, back rest and hip width are elaborated in core functionality. The device dimension and sub parts details were derived based on the ergonomic details, age groups, number of hours of usage, activity analysis and cultural issues of users (MIS).

The range of adjustments in seat width, depth, and foot height can accommodate a growing child up to 14 years of age. It is simple to disassemble and assemble the twin device. The device dismantles into 14 parts. A simple 10 mm spanner can be used to assemble the device. The device has a multipurpose tray to assist upright sitting or standing posture, and to encourage children to use hands to practice eating, writing, grasping, releasing, and in reaching skills. Proper positioning helps children with special needs communicate through speech or some form of nonverbal communication. For either type of communication, it is beneficial for children to be able to maintain eye contact with the listener. For speech, children must have adequate breath support for voice output. Proper trunk support allows the rib cage to expand better for breathing. The aesthetic designing of the device with warm emotional colors, organic materials, and themed giraffe finishing was done to attract the children.

Versatility

An appropriate positional device facilitates best anatomical alignment for the child, and also considers the child’s function. Correct device selection will allow the child’s functional communication and participation in his/her everyday environments, such as home, school, and community. Equipment must also be taken into consideration for transporting the child between these environments. The four sizes available in the twin devices can be adjusted to match children with delay in developmental milestone aged 2 to 14 years. Each size has features for adjusting the seat width, depth, and footrest. The possible range of adjustment in seat width and seat depth is 3 cm, while footrest height can be adjusted by 10 cm (Figure 4). The variants, size and height adjustment features of twin device was created using MIS database. The 3D modelling of the product was generated and reviewed by the team.

User trial

A 12 mm plywood material was selected for prototyping, at mobility India in 2014. The standard product preparation quality checklist was administered for twin device by the carpenter and AT assistant. The MIS database was used to develop a twin device. The prototyped device trial was conducted on a randomly selected child with delayed developmental milestones, Gross Motor Function Classification System (GMFCS VI). The child's immediate response to supported seating or standing with an orthosis on a twin device was to smile, praise, and clap. The mother felt at ease and relieved when she saw her child sit or stand on the device. The trial was focused on comfort, safety, and usability in seating and standing positions (Figure 5). This trial was helpful in determining if the device being considered best meets the needs of the child, if the size is appropriate, or if there is a need for certain customized modifications to maximize the benefits of the device. 

When selecting the proper device, it is important to keep in mind the amount of support the child will need from the device. If properly selected, the device can provide adequate support to substitute for the child's lack of motor control while providing him or her with adequate potential to be active in the chosen position. Too much control from the device limits the child's ability to move voluntarily. Not enough support from the device allows poor skeletal alignment, which will also limit the child's stability and movements.

QUEST

Quebec User Evaluation of Satisfaction with Assistive Technology –QUEST (Version 2.0) outcome measures were administered subsequent to three months of twin device usage. The QUEST has two major sections a) Assistive Device and b) Service. The outcome measures included 12 items. Scores were rated on a scale of - Not satisfied at all (1) to Very satisfied (5) (Annexure 1).⁸

Around 121 parents shared their QUEST feedback. The team carried out functional need assessment and prescribed twin device for children with delayed developmental milestones. Children with developmental disabilities, autism and pervasive developmental disorder, Down syndrome, and cerebral palsy, in the age range of 2-14 years, with GMFCS-IV, V, III were included. Subjects not satisfying inclusion criteria, those who were above 15 years of age, children who used the device for less than three months and GMFCS- I and II, were excluded.

A prospective qualitative study design was used in this study. Simple random sampling methods were used to recruit 255 parents of children with delayed milestones from 2016 to 2019. Children used the twin device as required. They were prospectively observed and the perceived effectiveness, usability, and service delivery system of twin device was collected from parents mostly through telephonic and in-person interviews after three months. If required, the user responses were verbally translated from regional languages.

Ethics & Funding

Mobility India received institutional approval to engage in this study. Participants received information about the study. Participants were informed that their participation was entirely optional and voluntary. It was made clear to the participants that they can opt out of the study at any point. They could decline to answer any questions of the interview if they felt uncomfortable responding. Participants were assured confidentiality of the data handling process. All participants provided their written, informed permission.

Statistical analysis

The data were subjected to descriptive and inferential statistical analysis. Continuous measurements were presented as mean±SD (Min-Max) and the categorical measurements were presented as Number (%). The level of significance was set at 5%. In correlation analysis, Spearman correlation coefficient test was applied for skewed distribution of data. The following assumptions on data were made: 1. Dependent variables are normally distributed, 2. Samples drawn from the population are random, and cases of the samples are independent. Statistical analysis was performed using SPSS 24.0.

Results

A total of 255 Children (84 girls and 171 boys) received the twin device from 2016 to 2019. However, 121 children (76 boys and 45 girls) aged between 3 to 12 years (mean age 10.9 years) responded to the QUEST survey. The distribution of GMFCS levels was as follows: III 28.0%, IV 49.0%, and V 23.0%. The distribution of subtypes was as follows: bilateral spasticity 66%, ataxia 8.5%, dyskinesia 15%, and unclassified or mixed kinds 10.5%. Table 1 provides more specific information about the distribution of age, sex, GMFCS level, and subtypes. Three age groupings of children were created.6 Significantly, disease severity was associated with age (r=0.458, p<0.001), CP type (r=0.445, p<0.001), GMFCS (r=0.229, p=0.006).

QUEST Survey scores

The parents were quite satisfied (4.48) with the twin device. The mean QUEST score of twin device was quite satisfied (4.16), and the score for service delivery of device was very satisfied (4.81). The parents reported being safe and secure (61.16%), easy to use (57.02%), and comfortable (56.2%) as the three most important features of the twin device. The Spearman’s correlation coefficient (rs = 0.736, p <0.003) testing the association between QUEST response levels was statistically significant.

Parent responses recorded using QUEST scoring device showed positive appraisals. The most accepted qualities of the twin device were safety, ease in use, comfort, and ease in adjustment. The twin device can support adequately in sitting and standing postures, reduce the burden on caregiver/parents and possibly facilitate hand to eye coordination, verbal and nonverbal communication and ADL functions like playing, eating, easy breathing, and arm & hand functions. The frequency and duration of the child's sitting and standing, as well as the time spent in each posture, requires further research. 60% of children with CP, aged 3 to 12 years use regular chairs and can sit down, stand up, and stand without any extra support. Positioning needs change as the children grow, have new medical needs, and/or gains new skills. Children require to be in several positions during the day. Different positions challenge or enable children to perform various skills.5,6 Proper positioning using adaptive device helps the child use more normal postures and movements to perform skills more easily. However, children need time out of their positioning device to move freely and to be held and cuddled. While their bodies are optimally positioned, children may be more successful in practicing and performing certain skills such as, visual tracking, grasping, eye hand coordination, playing with both hands, etc.

The QUSET responses on Innovation twin devices from different states of the country are tabulated below in Table 2. Quest responses from different states correlation coefficient was also statistically significant (rs = 0.654), (p <0.064).

Discussion

Assistive technology services are often in short supply and are located quite far from where children with disabilities live. In the global survey, 53% of 114 responding countries had not initiated programs relating to the provision of assistive technology. Current service delivery is not equitable. Inequities have been found not only between people living in different countries or regions of a country, or under different economic conditions, but also have been found among people with different impairments, genders, age groups, languages and cultures.¹⁰ There is lack of awareness among people with disabilities and their families regarding assistive products and services.¹ Limited access to the materials and equipment needed to produce assistive products can hamper production. Market-related factors can also limit production.⁹ The twin device was built using high-density polyethylene (HDPe) and wood plastic components (WPC) were used to check the feasibility, ease in customization and aesthetic look (Figure 7). These materials replaced painting to animal themed stickers.

However, product research and development is still required.¹⁰ Unless the design of an assistive product meets the child’s and the family’s needs and preferences, and is suitable in their physical, social, and cultural environment, there will continue to be a low demand for products. The twin device was also fabricated with mixture of plywood and HDPE/ WPC components (Figure 8). The WPC material is lightweight, childfriendly, and water-resistant. However, particle nature of WPC board could not withstand the load of the child and showed bowed, and nuts and bolts got loosened. HPDE was a resilient, strong, well-built material that allowed free rein while moulding the device into any cartoon or animal shape. It was difficult to handle, tough and heavy (Figure 8). Although a wide range of assistive products are available globally, their availability is restricted to few places, and all designs are not appropriate in all settings.

Currently, the market has limited awareness regarding assistive technology and the purchasing capacity leads to a limited demand. This results in incentives to engage in production. Local production may not be cost-effective as local markets are small.¹⁰

Suggestions to build the services and products that are adaptive, modifiable to suit the needs and requirements of individual children

Innovators need to accommodate differences in terms of individual factors (for example, health condition, body structure, body function, capacity, gender, age, ethnicity, and preference) as well as environmental factors (for example, physical environment, psychosocial environment, climate and culture).¹⁰ In addition, physical changes of children as they grow and develop need to be accommodated. How often a child should change an assistive product depends on how fast he or she develops and grows, which will vary over time and also between children. It is important to prevent new and secondary health problems such as pressure sores, pain, and deformities due to poorly adapted products.¹⁰

Recommendations to update the priority assistive products and ensure they reach children in need

Improve human resource capacity in the provision of assistive technology for children with disabilities. Provide adequate funding to improve availability and affordability of adaptive devices for children with disabilities. Increase awareness and understanding about adaptive devices for children with disabilities. Improve data collection and support research on assistive technology for children with disabilities.

Conclusion

Twin device and delivery services were of appropriate quality. Product qualities were measured through user satisfaction on strength, durability, capacity, safety and comfort. Provision of assistive technology includes the design, production and user satisfaction and quality of life. The twin device products and services were acceptable for children and their families. This was facilitated by involving them in the provision process and by considering their needs, preferences and expectations. Factors such as efficiency, reliability, simplicity, safety, comfort and aesthetics should be taken into account to ensure that devices and related services are acceptable for children and their families. Although needs, preferences and expectations are individual based, particularly regarding comfort and aesthetics, available designs should satisfy those of both girls and boys.

Conflict of Interest

The author(s) declare(s) that there is no conflict of interest. The children and their parents have provided informed consent and declared having no conflict of interest in the study.

Acknowledgement

We would like to thank the following individuals for their support and contribution to this research. Mr. Sama Raju, Physiotherapist, Asst, General Manager of Mobility India provided guidance and support in the research process. We would also like to thank our colleagues Mrs. Akkamma, Sr. Rehabilitation Therapy Assistant, Mrs. Leelavathi, Rehabilitation Therapy Assistant, Mrs. Savitri Paragi, Rehabilitation Therapy Assistant and Mr. Indra Sena Reddy, Developmental aid assistant at Mobility India for assisting in feedback collection. Finally, we would like to thank our Children with disabilities & their parents for participating in this study.